The present invention relates to a video disc player and, more particularly, to a linear tracking control system for a disc player.
A typical tracking control system is disclosed in Japanese Patent Laid Open Publication No. 50-130318 (corresponding to U.S. patent application Ser. No. 454,168 now U.S. Pat. No. 3,870,320 filed on Mar. 25, 1974), wherein a tracking drive operation is mechanically associated with rotation of a turntable upon which a video disc is mounted. More specifically, a fast drive timing belt and a playback drive timing belt are mechanically associated with a drive shaft of the turntable to transfer the rotation of the turntable to a drive mechanism of a playback transducer device. A playback drive solenoid, a fast forward drive solenoid and a fast reverse drive solenoid are provided for selectively driving the playback transducer device at three different modes.
Therefore, the conventional tracking control system is complicated and occupies a large space, because of provision of the three solenoids.
Accordingly, an object of the present invention is to provide a novel tracking control system for a disc player.
Another object of the present invention is to provide a simplified linear tracking system for a video disc player.
Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
To achieve the above objects, pursuant to an embodiment of the present invention, a playback transducer drive motor is provided in addition to a turntable drive motor. A tracking control system functions to selectively enable the playback transducer drive motor to selectively drive the playback transducer device at a playback mode, a fast forward mode or a fast reverse mode.
More specifically, in the fast forward mode, the playback transducer drive motor is rotated forward at a high speed. The playback transducer drive motor is rotated backward at a high speed in the fast reverse mode. In the playback mode, the playback transducer drive motor is intermittently rotated forward at a low speed. Under these three operation modes, the turntable is continuously driven to rotate at a fixed high speed by the turntable drive motor.
The above-mentioned selective drive can be performed by controlling the polarity and the amplitude of a drive signal to be applied to a D.C. motor. In a preferred form, the intermittent rotation of the playback transducer drive motor is controlled so that the playback transducer drive motor is rotated by a predetermined angle .theta. upon every four rounds of the turntable.